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The green smart city

The digital technologies helping plant life thrive in the urban environment

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Plant life in cities has many benefits—it can improve air quality and drainage, provide a source of food, and offer a welcome aesthetic respite from cityscapes dominated by concrete and glass. But competition for space in urban areas is fierce, with the need for housing and commercial property often encroaching on what little green space there is.

In the UK, for example, one study found that more than 54,000 acres of green space were converted to “artificial surfaces” between 2006 and 2012—an area twice the size of the city of Liverpool.

But the fightback has begun, with a growing trend towards green architecture. In 2014 the Bosco Verticale development in Milan opened to worldwide acclaim. The two residential buildings have more than 20,000 trees and plants integrated into their facades, all the way from ground level to the top of each 111 metre tower. If planted at ground level, the trees would cover an area of almost two acres. The skyscrapers were named the best tall buildings in the world in 2015.

Digital technology has an important role to play in the greening of the city. Satellite surveys and machine learning can help urban planners build a picture of the green space in their cities, while drones and RFID tags can make maintaining and protecting plant life easier and cheaper, even if it’s halfway up a skyscraper.

It’s now simpler than ever to build a picture of the amount of greenery in a city and identify areas where it could be improved. Researchers in London used infra-red satellite imagery, combined with data from Google Earth. Because plants and trees reflect infra-red light differently to man-made surfaces such as roads and roofs, this offered an easy way to build a map of existing green space in the city.

This technology can also help to identify candidates for the urban farms and green roofs that are springing up in cities across the world, where plants are grown on top of flat buildings. Berlin-based start-up Infarm, for instance, offers a modular, app-controlled hydroponic growing system that helps automate some previously manual processes on urban farms. Optigreen, another German company, has built an app that allows the precise control of the amount of water that drains down from a green roof.

Smart parks

Meanwhile, technology promises to help city authorities nurture their existing parks and other green spaces. While smart city initiatives have typically focused on transport infrastructure or the built environment, talk is now turning to “smart parks”.

One dimension of this is “smart irrigation”, the use of sensor networks and automation to ensure lawns and plants are watered in response to the weather and soil conditions. Such systems are already installed in city parks from Barcelona to Singapore.

The automation of plant care could soon be more conspicuous. In 2017 researchers in Shropshire planted and harvested an entire field of barley entirely with autonomous robots. In the future, information about the health of trees harvested by lightweight, low-powered sensors could be sent wirelessly to a field of drones, which would water and prune them without the need for human direction.

But there is more to “smart parks” than just looking after the plants. Green space is increasingly viewed as an essential determinant of wellbeing, and some initiatives focus on encouraging citizens to make better use of whatever greenery is available.

LA’s Interpretive Media Lab, for example, a joint venture between UCLA and California State Parks, created a mobile website that encouraged residents to explore the hidden history of the city’s parks and trails, in a bid to foster both community engagement and fitness. The UK city of Sheffield installed digital systems into its park-based exercise facilities to encourage participation.

In this way, technology can not only help plant life thrive in an urban environment, but also maximise its beneficial impact on the humans who live among it.